Highly cross-linked polymeric nanoparticles were prepared via novel one-step synthesis by copolymerizing ethylene glycol dimethacrylate (EGDMA) and the ionic liquid, 1-vinyl-3-(2-methoxy-2-oxyl ethyl) imidazolium chloride ([VMIm]Cl). The results indicated that nanoparticles with the average size of about 350 nm could be obtained conveniently through the cross-linking copolymerization. The nanoparticles were characterized using scanning electron microscopy, atomic force microscopy, Fourier transform Infrared, thermo gravimetric analysis, element analysis, and X-ray diffraction techniques. Moreover, the cross-linked polymeric nanoparticles were highly active and selective catalysts for the cycloaddition reaction of carbon dioxide to epoxides. The influences of reaction time, reaction temperature, CO2 pressure, and amount of catalyst on yield of the products were investigated. The results revealed that cyclic carbonates with high yield (98.4%) and selectivity (100%) could be produced on the condition of 0.1 g catalyst, 5 MPa CO2, 160 degrees C and 12 h. In addition, the nanocatalysts could be easily recovered by filtration, and reused several times with only slight loss of catalytic activity. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 1486-1493, 2012